A Spatial Econometrics Analysis for Road Accidents in Lisbon

This paper presents a spatial econometrics analysis for the number of road accidents with victims in the smallest administrative divisions of Lisbon, considering as a baseline a log-Poisson model for environmental factors. Spatial correlation on data is investigated for data alone and for the residuals of the baseline model without and with spatial-autocorrelated and spatial-lagged terms. In all the cases no spatial autocorrelation was detected.

Where is the economics in spatial econometrics?

Spatial econometrics has been criticized by some economists because some model specifications have been driven by data-analytic considerations rather than having a firm foundation in economic theory. In particular this applies to the so-called W matrix, which is integral to the structure of endogenous and exogenous spatial lags, and to spatial error processes, and which are almost the sine qua non of spatial econometrics. Moreover it has been suggested that the significance of a spatially lagged dependent variable involving W may be misleading, since it may be simply picking up the effects of omitted spatially dependent variables, incorrectly suggesting the existence of a spillover mechanism. In this paper we review the theoretical and empirical rationale for network dependence and spatial externalities as embodied in spatially lagged variables, arguing that failing to acknowledge their presence at least leads to biased inference, can be a cause of inconsistent estimation, and leads to an incorrect understanding of true causal processes.

Estimation of the Spatial Weights Matrix under Structural Constraints

While estimates of models with spatial interaction are very sensitive to the choice of spatial weights, considerable uncertainty surrounds de nition of spatial weights in most studies with cross-section dependence. We show that, in the spatial error model the spatial weights matrix is only partially identi ed, and is fully identifi ed under the structural constraint of symmetry. For the spatial error model, we propose a new methodology for estimation of spatial weights under the assumption of symmetric spatial weights, with extensions to other important spatial models. The methodology is applied to regional housing markets in the UK, providing an estimated spatial weights matrix that generates several new hypotheses about the economic and socio-cultural drivers of spatial di¤usion in housing demand.

General Equilibrium Long-Run Determinants for Spanish FDI: A Spatial Panel Data Approach

While general equilibrium theories of trade stress the role of third-country effects, little work has been done in the empirical foreign direct investment (FDI) literature to test such spatial linkages. This paper aims to provide further insights into long-run determinants of Spanish FDI by considering not only bilateral but also spatially weighted third-country determinants. The few studies carried out so far have focused on FDI flows in a limited number of countries. However, Spanish FDI outflows have risen dramatically since 1995 and today account for a substantial part of global FDI. Therefore, we estimate recently developed Spatial Panel Data models by Maximum Likelihood (ML) procedures for Spanish outflows (1993-2004) to top-50 host countries. After controlling for unobservable effects, we find that spatial interdependence matters and provide evidence consistent with New Economic Geography (NEG) theories of agglomeration, mainly due to complex (vertical) FDI motivations. Spatial Error Models estimations also provide illuminating results regarding the transmission mechanism of shocks.

Non-testability of equal weights spatial dependence

We show that any invariant test for spatial autocorrelation in a spatial error or spatial lag model with equal weights matrix has power equal to size. This result holds under the assumption of an elliptical distribution. Under Gaussianity, we also show that any test whose power is larger than its size for at least one point in the parameter space must be biased.

Testing for spatial autocorrelation: the regressors that make the power disappear

We show that for any sample size, any size of the test, and any weights matrix outside a small class of exceptions, there exists a positive measure set of regression spaces such that the power of the Cli-Ord test vanishes as the autocorrelation increases in a spatial error model. This result extends to the tests that dene the Gaussian power envelope of all invariant tests for residual spatial autocorrelation. In most cases, the regression spaces such that the problem occurs depend on the size of the test, but there also exist regression spaces such that the power vanishes regardless of the size. A characterization of such particularly hostile regression spaces is provided.

Multi-Agent Simulation of Urban Social Dynamics for Spatial Load Forecasting

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determining spatial resolution in spatial load forecasting using a grid-based model

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estimation of a preference map of new consumers for spatial load forecasting simulation methods using a spatial analysis of points

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Infant mortality in Brazil, 1980-2000: A spatial panel data analysis

Background: Infant mortality is an important measure of human development, related to the level of welfare of a society. In order to inform public policy, various studies have tried to identify the factors that influence, at an aggregated level, infant mortality. The objective of this paper is to analyze the regional pattern of infant mortality in Brazil, evaluating the effect of infrastructure, socio-economic, and demographic variables to understand its distribution across the country. Methods: Regressions including socio-economic and living conditions variables are conducted in a structure of panel data. More specifically, a spatial panel data model with fixed effects and a spatial error autocorrelation structure is used to help to solve spatial dependence problems. The use of a spatial modeling approach takes into account the potential presence of spillovers between neighboring spatial units. The spatial units considered are Minimum Comparable Areas, defined to provide a consistent definition across Census years. Data are drawn from the 1980, 1991 and 2000 Census of Brazil, and from data collected by the Ministry of Health (DATASUS). In order to identify the influence of health care infrastructure, variables related to the number of public and private hospitals are included. Results: The results indicate that the panel model with spatial effects provides the best fit to the data. The analysis confirms that the provision of health care infrastructure and social policy measures (e. g. improving education attainment) are linked to reduced rates of infant mortality. An original finding concerns the role of spatial effects in the analysis of IMR. Spillover effects associated with health infrastructure and water and sanitation facilities imply that there are regional benefits beyond the unit of analysis. Conclusions: A spatial modeling approach is important to produce reliable estimates in the analysis of panel IMR data. Substantively, this paper contributes to our understanding of the physical and social factors that influence IMR in the case of a developing country.

Spatial effects on rural commerce

Commerce in rural territories should not be considered as a needed service, but as a basic infrastructure, that impact not only existent population, but also tourism, and rural industrialization. So, the rural areas need not only agriculture but industry and services, to have a global and balanced development, including for the countryside and the population. In the work presented in this paper, we are considering the formulation of the direct relation between population and the endowment of commerce sites within a geographical territory, the ?area of commercial interactions?. These are the closer set of towns that can gravitate to each other to cover the required needs for the populations within the area. The products retailed, range from basic products for the daily lives, to all other products for industry, agriculture, and services. The econometric spatial model developed to evaluate the interactions and estimate the parameters, is based on the Spatial Error Model, which allows for other spatial hidden effects to be considered without direct interference to the commercial disposition. The data and territory used to test the model correspond to a rural area in the Spanish Palencia territory (NUTS-3 level). The parameters have dependence from population levels, local rent per head, local and regional government budgets, and particular spatial restrictions. Interesting results are emerging form the model. The more significant is that the spatial effects can replace some number of commerce sites in towns, given the right spatial distribution of the sites and the towns. This is equivalent to consider the area of commercial interactions as the unit of measurement for the basic infrastructure and not only the towns.

A Spatial Analysis of Agricultural Land Prices in Bavaria. Factor Markets Working Document No. 50, June 2013

This paper empirically analyses a dataset of more than 7,300 agricultural land sales transactions from 2001 and 2007 to identify the factors influencing agricultural land prices in Bavaria. We use a general spatial model, which combines a spatial lag and a spatial error model, and in addition account for endogeneity introduced by the spatially lagged dependent variable as well as other explanatory variables. Our findings confirm the strong influence of agricultural factors such as land productivity, of variables describing the regional land market structure, and of non-agricultural factors such as urban pressure on agricultural land prices. Moreover, the involvement of public authorities as a seller or buyer increases sales prices in Bavaria. We find a significant capitalisation of government support payments into agricultural land, where a decrease of direct payments by 1% would decrease land prices in 2007 and 2001 by 0.27% and 0.06%, respectively. In addition, we confirm strong spatial relationships in our dataset. Neglecting this leads to biased estimates, especially if aggregated data is used. We find that the price of a specific plot increases by 0.24% when sales prices in surrounding areas increase by 1%.

Aglomeração econômica e disparidade salarial no Espírito Santo : teoria e evidência a partir de um enfoque da Nova Geografia Econômica

O trabalho buscou analisar questões de desigualdade regional no Espírito Santo através da linha de pesquisa denominada Nova Geografia Econômica (NGE). Uma forma de realizar essa análise é através do estudo da relação entre diferenciais de salário e mercado potencial. Mais precisamente, o trabalho procurou verificar o impacto de fatores geográficos de segunda natureza – mercado potencial – nos salário médios municipais. Inicialmente, por meio de uma Análise Exploratória de Dados Espaciais, verificou-se que os salários são maiores próximos às regiões com alto mercado potencial (litoral/RMGV). Por meio da utilização de técnicas de estatística e econometria espacial foi possível observar para os anos de 2000 e 2010 a existência de uma estrutura espacial de salários no Espírito Santo. O coeficiente de erro autorregressivo foi positivo e estatisticamente significativo, indicando o modelo SEM (spatial error model) como o mais apropriado para modelar os efeitos espaciais. Os resultados indicam ainda que não só fatores educacionais afetam os salários, fatores geográficos de segunda natureza possuem um efeito até maior quando comparados aos primeiros. Conclui-se, como demonstra o modelo central da NGE que, forças exclusivamente de mercado nem sempre levam ao equilíbrio equalizador dos rendimentos, pelo contrário, levam à conformação de uma estrutura do tipo centro-periferia com diferença persistente de rendimentos entre as regiões. Adicionalmente, verifica-se que os municípios que apresentam maior salário, maior mercado potencial e melhores indicadores sociais são àqueles localizados no litoral do estado, mais precisamente os municípios próximos à RMGV. Sendo assim, o trabalho reforça a necessidade de que se pense estratégias que fomentem a criação de novas centralidades no Espírito Santo, a fim de atuar na redução das desigualdades regionais. O trabalho se insere num grupo de vários outros estudos que analisaram questões de desigualdade e concentração produtiva no Espírito Santo. A contribuição está na utilização do referencial teórico da NGE, que ainda não havia sido empregada para o estado, e na utilização de técnicas de estatística espacial e econometria espacial.

Research networks and inventors’ mobility as drivers of innovation evidence from Europe

We investigate the importance of the labour mobility of inventors, as well as the scale, extent and density of their collaborative research networks, for regional innovation outcomes. To do so, we apply a knowledge production function framework at the regional level and include inventors’ networks and their labour mobility as regressors. Our empirical approach takes full account of spatial interactions by estimating a spatial lag model together, where necessary, with a spatial error model. In addition, standard errors are calculated using spatial heteroskedasticity and autocorrelation consistent estimators to ensure their robustness in the presence of spatial error autocorrelation and heteroskedasticity of unknown form. Our results point to the existence of a robust positive correlation between intraregional labour mobility and regional innovation, whilst the relationship with networks is less clear. However, networking across regions positively correlates with a region’s innovation intensity.

Représentation interne des caractéristiques physiques d'un objet

Dans les situations du quotidien, nous manipulons fréquemment des objets sans les regarder. Pour effectuer des mouvements vers une cible précise avec un objet à la main, il est nécessaire de percevoir les propriétés spatiales de l’objet. Plusieurs études ont démontré que les sujets peuvent discriminer entre des longueurs d'objet différentes sans l’aide des informations visuelles et peuvent adapter leurs mouvements aux nouvelles caractéristiques inertielles produites lors de la manipulation d’un objet. Dans cette étude, nous avons conduit deux expérimentations afin d’évaluer la capacité des sujets à adapter leurs mouvements d’atteinte à la longueur et à la forme perçues des objets manipulés sur la base unique des sensations non visuelles (sensations haptiques). Dans l'expérience 1, dix sujets devaient exécuter des mouvements d’atteintes vers 4 cibles tridimensionnelles (3D) avec un objet à la main. Trois objets de longueur différente ont été utilisés (pointeurs: 12.5, 17.5, 22.5 cm). Aucune connaissance de la position de la main et de l’objet par rapport à la cible n’était disponible pendant et après les mouvements vers les cibles 3D. Ainsi, lorsque comparé avec les erreurs spatiales commises lors des atteintes manuelles sans pointeur, l’erreur spatiale de chacun des mouvements avec pointeur reflète la précision de l’estimation de la longueur des pointeurs. Nos résultats indiquent que les sujets ont augmenté leurs erreurs spatiales lors des mouvements d’atteinte avec un objet en comparaison avec la condition sans pointeur. Cependant, de façon intéressante, ils ont maintenu le même niveau de précision à travers les trois conditions avec des objets de différentes longueurs malgré une différence de 10 cm entre l’objet le plus court et le plus long. Dans l'expérience 2, neuf sujets différents ont effectué des mouvements d’atteinte vers les mêmes cibles utilisant cette fois-ci deux objets en forme de L (objet no.1 : longueur de 17,5 cm et déviation à droite de 12,5 cm – objet no.2 : longueur de 17,5 cm et déviation à droite de 17,5 cm). Comme c’était le cas lors de l'expérience 1, les sujets ont augmenté leurs erreurs spatiales lors des mouvements d’atteinte avec les objets et cette augmentation était similaire entre les deux conditions avec les objets en forme de L. Une observation frappante de l’expérience 2 est que les erreurs de direction n’ont pas augmenté de façon significative entre les conditions avec objet en forme de L et la condition contrôle sans objet. Ceci démontre que les participants ont perçu de façon précise la déviation latérale des objets sans jamais avoir eu de connaissances visuelles de la configuration des objets. Les résultats suggèrent que l’adaptation à la longueur et à la forme des objets des mouvements d’atteinte est principalement basée sur l’intégration des sensations haptiques. À notre connaissance, cette étude est la première à fournir des données quantitatives sur la précision avec laquelle le système haptique peut permettre la perception de la longueur et de la forme d’un objet tenu dans la main afin d’effectuer un mouvement précis en direction d’une cible.